This invention is concerned with a severing mechanism operable to sever gobs from a column of molten glass issuing from a feeder.
In the manufacture of glass containers, molten glass is produced in a furnace and flows from the furnace along a forehearth where it is brought to the desired temperature. At one end of the forehearth a feeder is provided which controls the flow of molten glass out of the forehearth in one or more columns The columns of glass are severed by a severing mechanism into individual gobs of molten glass, each gob containing sufficient glass to make one container, and the severed gobs are fed under gravity to a moulding machine. If the machine is arranged to make one container at a time, one column of glass is provided and one gob at a time is separated, but the machine may be arranged to make two, three or even four containers at a time, in which case there will be a corresponding number of columns and a corresponding number of gobs separated at one time.
Commonly the severing mechanism comprises two opposed blades for each column which are moved simultaneously towards the column from opposite sides thereof into an overlapping condition to shear against each other and thus to separate a gob from the column Frequently, the blades are moved arcuately, but in general because the blades are brought into overlapping rest positions in the column to shear it, the blades are moved comparatively slowly in the glass and are thus less efficient in their severing action than a fast moving blade.
In U.S. Pat. specification No. 3 996 037 there is described a shearing mechanism operable to shear gobs from a column of molten glass which comprises two blades each having a first cutting edge along one side of the blade and a second cutting edge along the other side of the blade and means for moving the blades simultaneously in opposite directions along linear paths each from opposite sides of the column to the other thus to separate a gob by the shearing action of the two blades passing through the column. This shearing mechanism requires not only two blades but also mechanism for moving the blades simultaneously in opposite directions and mechanism for adjusting the vertical distance between the blades.
It is one of the objects of the present invention to provide a particularly simple construction of severing mechanism operable to sever gobs from a column of glass.